1,1,1-Trihalogeno-4-methylpentenes, method of preparing the same and use of the same in the preparation of 1,1-dihalogeno-4-methyl-1,3-pentadienes

ABSTRACT

1,1,1-Trihalogeno-4-methyl pentenes and 1,1-dihalogeno-4-methyl-1,3-pentadienes are produced. These compounds are of value as intermediates for the production of pyrethrin analogs which are of use as insecticides or agricultural chemicals.

The present invention relates to 1,1,1-trihalogeno-4-methylpentenes, amethod for producing the same, and a method for producing1,1-dihalogeno-4-methyl-1,3-pentadienes from1,1,1-trihalogeno-4-methylpentenes.

1,1,1-Trihalogeno-4-methylpentenes according to the present inventionare novel compounds having the general formula: ##STR1## (wherein X¹, X²and X³ are the same or different and each represents a halogen atom; Zstands for a group of the formula: ##STR2## or a group of the formula:##STR3##

Referring to general formula [I], X¹, X² and X³, respectively, stand fora chlorine, bromine, fluorine or iodine atom, the preferred speciesbeing chlorine and bromine. The 1,1,1-trihalogeno-4-methylpentenesrepresented by general formula [I] are of value as starting materialsfor the production of various important compounds.

Among the compounds of general formula [I],1,1,1-trihalogeno-4-methyl-3-pentenes in particular are importantintermediates for the synthesis of dihalogenovinyl chrysanthemumateswhich, as will be explained hereinafter, have recently come to claimattention as insecticides or agricultural chemicals and are of valuealso as intermediates for the synthesis of terpenoids. Furthermore,1,1,1-trihalogeno-4-methyl-4-pentenes, after isomeric conversion to1,1,1-trihalogeno-4-methyl-3-pentenes, are similarly of use asintermediates for the synthesis of dihalogeno-vinyl chrysanthemumatesand other compounds. Dihalogeno-vinyl chrysanthemumates have high andsustained insecticidal activity against various species of insects incontrast to natural pyrethroid insecticides which are susceptible tophotolysis [M. Elliot et al, Nature 244, 456 (1973)].

As a process for the synthesis of dihalogeno-vinyl chrysanthemumates,Japanese Patent Application Laid Open No. 47531/1974 (corresponding toGer. Pat. Appl. Laid Open No. 2326077) recently teaches a process whichcomprises oxidizing chrysanthemummonocarboxylic acid with ozone andsubjecting the resultant .[.correspnding.]. .Iadd.corresponding.Iaddend.aldehyde to the Wittig reaction. This process, however, isgenerally thought to be hardly adaptable to commercial productionbecause it requires not only a costly starting material, i.e.chrysanthemummonocarboxylic acid but such time-consuming reactions asoxidation with ozone and Wittig reaction.

Also recently disclosed is a process which comprises permitting anorthocarboxylic acid ester to act upon 3-methyl-2-buten-1-ol, thenadding a tetrahalogenomethane to the reaction product and cyclizing theresultant adduct with alkali to obtain a cyclopropanecarboxylate. Sincethis process requires only a few reaction steps, each providing a goodyield, it might appear to be commercially profitable. However, thisprocess also has much to be desired partly because, up to this time, noeffective synthetic route to the starting material.[.3-methyl-2-buten-1-1-ol.]. .Iadd.3-methyl-2-buten-1-ol .Iaddend.isknown and partly because of the high prices of orthocarboxylic acidesters.

J. Farkas et al report a diazoacetic acid process in Collect. Czech.Chem. Commun. 24, 2230 (1959) (hereinafter referred to as Farkasprocess). This process comprises acetylating1,1,1-trichloro-4-methyl-3-penten-2-ol, reducing the acetylation producewith zinc-acetic acid to obtain 1,1-dichloro-4-methyl-1,3-pentadieneand, then in a conventional manner, reacting the last-mentioned compoundwith diazoacetic acid or an ester thereof to obtain acyclopropanecarboxylic acid or an ester thereof. This process is notcommercially profitable, either, for it involves a time-consuming seriesof reactions for the synthesis of 1,1-dichloro-4-methyl-1,3-pentadieneand, also, a complicated procedure, i.e. reduction with zinc-aceticacid.

The research undertaken by us to develop a method for economicalproduction of dihalogeno-vinyl chrysanthemumates led to the discovery ofa synthetic intermediate which is instrumental in realizing a markedimprovement in the Farkas process.

Thus, 1,1,1-trihalogeno-4-methyl-3-pentenes are considerably superior toconventional 1,1,1-trihalogeno-2-acetoxy-4-methyl-3-pentenes asintermediate materials for the production of1,1-dihalogeno-4-methyl-1,3-pentadienes according to the Farkas process.When a 1,1,1-trihalogeno-4-methyl-3-pentene is employed, this materialcan be easily converted to the 1,1-dihalogeno-4-methyl-1,3-pentadiene ofgeneral formula [II] by a simple procedure, i.e. treatment with a basicreagent, as compared to the conventional costly and complicatedprocedure, i.e. using a stoichiometric amount of zinc for the reductionof a 1,1,1-trihalogeno-2-acetoxy-4-methyl-3-pentene with zinc-aceticacid. ##STR4## (wherein X and Y, respectively, represent one of X¹, X²and X³ of general formula [I])

As examples of said basic reagent, there may be mentioned alkali metalor alkaline earth metal hydroxides such as sodium hydroxide, potassiumhydroxide, calcium hydroxide, barium hydroxide, etc.; alkali metalalcoholates such as sodium methoxide, sodium ethoxide, potassiummethoxide, sodium tert-butoxide, potassium tert-butoxide, sodiumtert-amyloxide, etc.; alkali metal hydrides such as sodium hydride,potassium hydride, etc.; alkali metal amindes such as sodium amide,etc.; organic amines such as 1,5-diazabicyclo[3,4,0]nonene-5 (brieflyDBN), 1,5-diazabicyclo[5,4,0]undecene-5(briefly OBU),2-dimethylamino-1-pyrroline, etc.; and organolithium compounds such asn-butyllithium, s-butyllithium, diisopropylaminolithium, and so forth.From the standpoints of economy and reaction efficiency, it ispreferable to employ alkali metal alcoholates, alkali metal hydrides oralkali metal hydroxides. The proportion of said basic reagent is atleast one molecular equivalent and, preferably, within the range of 1 to2 equivalents.

The reaction is preferably carried out in a solvent. As examples of saidsolvent, there may be mentioned aqueous solvents; alcohol solvents suchas methanol, ethanol, etc.; aprotonic polar solvents such asN,N-dimethylformamide (hereinafter DMF), dimethylsulfoxide (brieflyDMSO), etc.; and hydrocarbons such as benzene, toluene and so forth.When the basic reagent is an organic amine, it may be used in excess sothat it will act also as a solvent. The reaction temperature is betweenroom temperature and 150° C., preferably within the range of 50° to 130°C.

As illustrated hereinafter, a 1,1,1-trihalogeno-4-methyl-3-pentene maybe reacted with diazoacetic acid or an ester thereof in a mannerconventional per se and, then, the reaction product bede-hydrohalogenated to obtain the corresponding dihalogeno-vinylchrysanthemumic acid or an ester thereof. ##STR5## (wherein X and Y,respectively, represent one of X¹, X² and X³ ; and R is a hydrogen atomor an alcohol residue)

The 1,1,1-trihalogeno-4-methylpentenes [I] of the present invention maybe produced by removing R'OH from compounds of general formula [III]:##STR6## (wherein R¹ is a hydrogen atom or an alkyl, cycloalkyl, aryl,aralkyl or acyl group; X¹, X² and X³ have the same meanings as definedin general formula [I]).

More particularly, compounds of general formula [III] are such that R¹is a hydrogen atom, an alkyl group of 1 to 20 carbon atoms, a cycloalkylgroup of 6 to 20 carbon atoms, an aryl group of 6 to 15 carbon atoms, anaralkyl group of 7 to 20 carbon atoms or an acyl group of 1 to 10 carbonatoms, preferably representing hydrogen, methyl, ethyl, propyl, butyl,acetyl, propionyl, or butyryl, and X¹, X² and X³, respectively, arepreferably chlorine or bromine.

The reaction by which R¹ OH is removed from a compound of generalformula [III] is (i) dehydration where R¹ is a hydrogen atom, (ii)dealcoholation where R¹ is an alkyl, cycloalkyl, aryl or aralkyl group,and (iii) decarboxylation where R¹ is an acyl group.

The above dehydration, dealcoholation or decarboxylation reaction may beeasily accomplished by heating a compound of general formula [III] inthe presence of a strongly acid to weakly acid catalyst such as sulfuricacid, phosphoric acid, p-toluenesulfonic acid, phosphorus pentoxide,vanadium pentoxide, wolfram trioxide, etc. at a temperature ranging fromroom temperature to 120° C. or, alternatively, heating the same eitherin gaseous phase or in liquid phase in the presence of silica gel,aluminum silicate, kieselguhr, pumice, Fuller's earth, activatedalumina, activated carbon or the like at a temperature from 80° to 250°C. In the latter case, Kieselguhr, for instance, may be used incombination with vanadium pentoxide, for instance, in the form of asupported catalyst to hasten the reaction.

The aforementioned catalysts is used in a proportion of 0.01 to 30weight percent, preferably 0.1 to 10 weight percent, based on compoundof general formula [III].

While the composition of the reaction product varies somewhat accordingto the conditions of reaction, the dehydration, dealcoholation ordecarboxylation of compounds of general formula [III] yields, asprincipal product compounds, 1,1,1-trihalogeno-4-methyl-3-pentene ofgeneral formula [I']: ##STR7## and 1,1,1-trihalogeno-4-methyl-4-penteneof general formula [I"]: ##STR8##

In addition, byproducts such as 1,1-dihalogeno-4-methyl-1,3-pentadiene,etc. are also produced in minor amounts.

Normally, the total selectivity for compound [I'] and compound [I"] isnot less than 98 percent at a conversion of not less than 95 percentbased on compound of general formula [III]. The ratio of1,1,1-trihalogeno-4-methyl-3-pentene to1,1,1-trihalogeno-4-methyl-4-pentene in the reaction product is normallywithin the range of 3:2 to 9:1, and by fractional distillation,1,1,1-trihalogeno-4-methyl-3-pentene can be isolated in high purity. Inconnection with this procedure, it is of utmost significance, for thepurpose of producing a starting material for1,1-dihalogeno-4-methyl-1,3-pentadiene, to isomerize the1,1,1-trihalogeno-4-methyl-4-pentene, which is obtainable as a firstdistillate in the above procedure, to the corresponding1,1,1-trihalogeno-4-methyl-3-pentene.

If this first distillate rich in 1,1,1-trihalogeno-4-methyl-4-pentene isreturned to the reaction system of compound [III] in the presence of theaforementioned acid catalyst, it will isomerize to1,1,1-trihalogeno-4-methyl-3-pentene. In this manner1,1,1-trihalogeno-4-methyl-3-pentene can be produced in good yield.

The isomerization of 1,1,1-trihalogeno-4-methyl-4-pentene to1,1,1-trihalogeno-4-methyl-3-pentene may also be accomplished in anindependent reaction step. In such a process, the reaction may beconducted between about 80° C. and about 200° C. particularly preferredis a temperature range of about 110° to 170° C. This isomerizationreaction proceeds with heating time until finally it yields anequilibrium composition corresponding to the temperature employed.

While said isomerization reaction proceeds under heating even in theabsence of a catalyst, the following procedure may be followed to obtaina significantly increased rate of isomerization and to drasticallyreduce the reaction time required before an equilibrium composition or aconversion rate approaching it is obtained. Thus, the reaction systemmay be heated in the presence of, as a catalyst, at least a memberselected from the class consisting of transition metals of Group 6B,Group 7B and Group 8 of Periodic Table of the Elements (such as Cr, Mn,Co, Ni, Ru, Ph, Pd, W, Ir, etc.) and compounds (e.g. oxides, inorganicacid salts, organic acid salts, complex compounds, etc.) of suchtransition metals. As an alternative, the reaction system may be heatedin the presence of an acid catalyst such as sulfuric acid, phosphoricacid, boric acid, p-toluenesulfonic acid, acetonedisulfonic acid or thelike.

Referring to the catalysts thus employable, the compounds of transitionmetals of Group 6B, Group 7B and Group 8 are exemplified by chromium(III) acetylacetonate, molybdenum disulfide, wolfram trioxide, manganese(III) acetylacetonate, ruthenium trichloride, cobalt (II)acetylacetonate, cobalt hexamine chloride, rhodium (III)acetylacetonate, rhodium trichloride, iridium trichloride, Raney nickel,nickel (II) acetylacetonnate, palladium chloride, palladium black,palladium oxide, palladium acetate, 5% palladium-on-carbon and so forth.The catalyst may be employed in an amount ranging from 0.001 to 30weight percent based on compound [I"] and, preferably, 0.1 to 10 weightpercent on the same basis. The isomerization reaction may be carried outeither batchwise or continuously.

A compound [III] may be produced by adding a haloform to dimethyl vinylcarbinol or a derivative thereof, of general formula [IV], underconditions of radical reaction. ##STR9## (wherein R¹ is as defined ingeneral formula [III])

The said conditions of radical reaction may be established by allowing aradical initiator to be present in the reaction system or byirradiation. As said radical initiator, there may be mentioned benzoylperoxide (BPO), azobisisobutyronitrile (AIBN), acetyl peroxide,di-tert-butyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxideand so forth. The radical initiator serves the purpose when used in acatalytic amount. The reaction may be conducted in the atmosphere or,alternatively, in an inert gas such as carbon dioxide, nitrogen, heliumor the like.

The haloforms that are preferred for the purposes of this reaction arechloroform and bromoform. It is sufficient to employ a molecularequivalent of haloform based on compound of general formula [IV],although 2 to 20 equivalents of haloform may be employed, in which casethe haloform will act also as a reaction solvent. Although a reactionsolvent is not indispensable, there may be employed a solvent that willnot directly interfere with the contemplated reaction, such solventbeing exemplified by carbon disulfide, n-hexane, n-heptane and so forth.The reaction temperature is preferably somewhere between roomtemperature and 100° C. when the reaction is initiated by irradiation,or from 70° to 180° C. when a radical reaction initiator is employed.

Radical-addition reactions of halides, esters, alcohols, activemethylene, etc. to olefins are well known and, broadly, the followingtwo general procedures are available.

a. Heating in the presence of both of an organic amine and a transitionmetal compound;

b. Heating in the presence of a radical reaction initiator

The first procedure (a) is not applicable from a selectivity point ofview. Thus, under the conditions of (a), the addition of the haloform asX. and .CHX₂ radicals predominates. The .[.hithereto.]. .Iadd.hitherto.Iaddend.attempted radical-addition reaction of a haloform to an allylicalcohol, ether or ester yields a large proportion of telemer, forexample as reported by Kharasch et al in J. Am. Chem. Soc. 69, 1105(1947) and described by Lewis et al in J. Am. Chem. Soc. 76, 457 (1954),and the yield of 1:1 .[.abjuct.]. .Iadd.adduct .Iaddend.is as low as 20to 30 percent as stated by Tarrant et al in J. Org. Chem. 26, 4646(1961). Furthermore, it is known that a tertiary allylic alcohol such asdimethyl vinyl carbinol is ready to induce a dehydration reaction underheating. Notwithstanding this, subjecting a compound of general formula[IV] and a haloform together to the above-mentioned radical-reactionconditions enables one to selectively obtain a compound of generalformula [III] without causing a dehydration reaction or beingaccompanied by telomerization. By way of illustration, we added a smallamount of benzoyl peroxide (BPO) to 8.6 g of dimethyl vinyl carbinol in50 ml of chloroform and reacted the mixture of 140° C. and in a nitrogenatmosphere for 16 hours. Gas-chromatographic analysis of the reactionproduct mixture revealed that the conversion of dimethyl vinyl carbinolwas 78.2 percent and the selectivity for1,1,1-trichloro-4-methyl-4-hexanol was 94.5 percent.

1,1,1-Trihalogeno-4-methyl-3-pentenes may be produced by the followingprocedure as well, although this procedure is less advantageous than theabove procedure starting with compounds of general formula [III] in thatthe former procedure gives rise to larger amounts of byproducts. Thus, a1,1,1-trihalogeno-4-methyl-3-pentene may be produced by heating atertiary allyl halide of general formula [V] together with atetrahalogenomethane under radical reaction conditions. ##STR10##(wherein X⁴ is a halogen atom)

The above procedure entails production of a large proportion of abyproduct compound of general formula [VI]: ##STR11## (wherein X¹, X²and X³ have the same meanings as defined in general formula [I]; X⁴ hasthe same meaning as defined in general formula [V]; and X⁵ is a halogenatom)

The present invention will be further illustrated by way of thefollowing examples, in which, unless otherwise specified, all NMRspectra were determined at 60 MHZ in carbon tetrachloride at roomtemperature, with tetramethylsilane as the internal reference.

EXAMPLE 1

To a solution of 17.2 g of dimethyl vinyl carbinol in 150 ml ofchloroform was added 0.8 g of benzoyl peroxide and, in an autoclave, themixture was reacted at 135° C. and in a nitrogen atmosphere for 18hours. Then, the unreacted dimethyl vinyl carbinol and chloroform wereremoved by distillation under reduced pressure. As the residue wasobtained 30.1 g of a dark-reddish viscous fluid. This residue wassubjected to vacuum distillation to obtain 28.2 g (yield 69%) of1,1,1-trichloro-4-pentanol. Gas-chromatographic analysis of this productshowed its purity to be 95.4%. mass spectrometric data suggested thatthe impurity comprised 1,1,3-trichloro-4-methyl-4-pentanol. Thefollowing procedures were used for structural identification of1,1,1-trichloro-4-methyl-4-pentanol.

    ______________________________________                                        Infrared absorption spectrum:                                                  ##STR12##                                                                    Mass spectrum:                                                                 ##STR13##                                                                    Nuclear magnetic resonance spectrum: δ (in CCl.sub.4, ppm)               ##STR14##                                                                    ______________________________________                                    

Then, 0.1 g of p-toluenesulfonic acid was added to a solution of 10 g of1,1,1-trichloro-4-methyl-4-pentanol in 50 ml of benzene, and the mixturewas heated under reflux for 2 hours, the byproduct water beingazeotropically removed. Following the reaction, the solvent wasdistilled off under reduced pressure and the residue was distilled invacuo. The procedure provided 8.5 g (yield 92%) of a mixture of1,1,1-trichloro-4-methyl-4-pentene and1,1,1-trichloro-4-methyl-3-pentene as a fraction boiling at 74°-77° (19mmHg). Gas-chromatographic analysis of this fraction revealed that itcomprised 1,1,1-trichloro-4-methyl-4-pentene and1,1,1-trichloro-4-methyl-3-pentene in a ratio of about 33 to 67. Thismixture was fractionated by fractional distillation and each fractionwas identified by the following procedures.

    ______________________________________                                         ##STR15##                                                                    Infrared absorption spectrum (neat)                                            ##STR16##                                                                    Mass spectrum                                                                  ##STR17##                                                                    Nuclear magnetic resonance spectrum: δ (in CCl.sub.4, ppm)               ##STR18##                                                                    Infrared absorption spectrum (neat)                                            ##STR19##                                                                    Mass spectrum                                                                  ##STR20##                                                                    Nuclear magnetic resonance spectrum: δ (in CCl.sub.4, ppm)               ##STR21##                                                                    ______________________________________                                    

EXAMPLES 2 to 8

5.0 g of 1,1,1-trichloro-4-methyl-4-pentanol, as obtained by a proceduresimilar to that described in Example 1, were subjected to dehydrationreaction under various conditions. The results are set forth in Table 1.

In Examples 2, 6 and 7, the byproduct water was azeotropically removedfrom the reaction system.

                  TABLE 1                                                         ______________________________________                                                         Dehy-   Conditions    *                                           Reaction    drating of dehy-                                                                              %     4-Pentene/                             Ex.  solvent     agent   dration Yield 3-pentene                              ______________________________________                                        2    C.sub.6 H.sub.6                                                                           conc    reflux, 91    33/67                                       25 ml       H.sub.2 SO.sub.4                                                                      2.0 hr                                                                50 mg                                                        3    Diethyl     conc    reflux, 83    28/72                                       ether       H.sub.2 SO.sub.4                                                                      1.5 hr                                                    25 ml       1.0 g                                                        4    CH.sub.3 C.sub.6 H.sub.5                                                                  P.sub.2 O.sub.5                                                                       reflux, 87    36/64                                       25 ml       50 mg   3.0 hr                                               5    Diethyl     P.sub.2 O.sub.5                                                                       reflux, 86    30/70                                       ether       80 mg   6.0 hr                                                    25 ml                                                                    6    C.sub.6 H.sub.6                                                                           V.sub.2 O.sub.5                                                                       reflux  87    35/65                                       25 ml       30 mg   8.0 hr                                               7    C.sub.6 H.sub.6                                                                           WO.sub.3                                                                              reflux, 89    35/65                                       25 ml       20 mg   6.0 hr                                               8    (CH.sub.3).sub.2 C.sub.6 H.sub.4                                                          SiO.sub.2                                                                             reflux, 84    40/60                                       25 ml       1.0 g   4.0 hr                                               ______________________________________                                         *1,1,1-Trichloro-4-methyl-4-pentene/1,1,1-trichloro-4-methyl-3-pentene   

EXAMPLES 9 to 18

As in Example 1, various dimethyl vinyl carbinol compounds were reactedwith a haloform under various radical reaction conditions. Followingrecovery of the excess haloform and unreacted dimethyl vinyl carbinolcompound, the residue was not purified but directly subjected to thenext reaction for removal of R¹ OH. The results are summarized in Table2. In all instances, the radical-addition reaction was conducted in aninert gaseous atmosphere.

                                      TABLE 2                                     __________________________________________________________________________     Ex.                                                                              ##STR22##                                                                              (g)Haloform                                                                        (g)initiatorRadical                                                                additionradicaloftionsCondi-                                                       ##STR23##                                                                              (Yield)%*                                                                         .Iadd.R.sup.1 OH.Iaddend.of                                                  .[.R.sub.1 OH.].of                                                            removalConditions                                                                         ##STR24##                                                                             Δ.sup.3                                                                -)(Δ.sup.                                                               4 -/Yield**        __________________________________________________________________________     9 R.sup.1 = H (8.6)                                                                      Chloro- form (200)                                                                 BPO (0.2)                                                                          170° C., 18 hr                                                               ##STR25##                                                                             (89.6)                                                                            p-Toluenesulfonic acid 0.05 g                                                 C.sub.6 H.sub.6 25 ml reflux, 1.5                                             hr         92.6    (33/67)            10 R.sup.1 = H (8.6)                                                                      Bromo- form (50)                                                                   t.Butyl perace- tate (0.2)                                                         120° C., 8 hr                                                                ##STR26##                                                                             (83.3)                                                                            P.sub.2 O.sub.5 0.2 g C.sub.6                                                 H.sub.6 25 ml reflux, 3                                                                  90.3    (33/65)            11                                                                                ##STR27##                                                                             Chloro- form (100)                                                                 BPO (0.4)                                                                          150° C., 12 hr                                                               ##STR28##                                                                             (76.2)                                                                            conc. H.sub.2 SO.sub.4 0.1 g                                                  CH.sub.3 C.sub.6 H.sub.5 25 ml                                                reflux, 2 hr                                                                             94.1    (35/65)            12                                                                                ##STR29##                                                                             Chloro- form (100)                                                                 AIBN (0.3)                                                                         160° C., 12 hr                                                               ##STR30##                                                                             (73.8)                                                                            P-Toluenesulfonic acid 0.1 g                                                  CCl.sub.4 25 ml reflux, 3                                                                93.8    (33/67)            13                                                                                ##STR31##                                                                             Bromo- form (50)                                                                   BPO (0.2)                                                                          130° C., 8 hr                                                                ##STR32##                                                                             (82.6)                                                                            conc. H.sub.2 SO.sub.4 0.5 g                                                  C.sub.2 H.sub.5 OC.sub.2 H.sub.5                                              50 ml reflux, 5                                                                          91.1    (30/70)            14 R.sup.1 = CH.sub.2 C.sub.6 H.sub.5 (15)                                                Chloro- form (200)                                                                 t-Butyl perben- zoate (0.3)                                                        130° C., 18 hr                                                               ##STR33##                                                                             (77.4)                                                                            conc. H.sub.2 SO.sub.4 0.5 g                                                  C.sub.2 H.sub.5 OC.sub.2 H.sub.5                                              50 ml reflux, 6                                                                          86.7    (28/72)            15 R.sup.1 = CH.sub.3 (10)                                                                Chloro- form (200)                                                                 Cumene hydro- peroxide (0.5)                                                       140° C., 16 hr                                                               ##STR34##                                                                             (69.6)                                                                            Conc. H.sub.2 SO.sub.4 0.1 g No                                               solvent 90° C., 8                                                                 85.5    (32/68)            __________________________________________________________________________     Ex.                                                                              ##STR35##                                                                              (g)Haloform                                                                        (g)initiatorRadical                                                                additionradicaloftionsCondi-                                                       ##STR36##                                                                              (Yield)%*                                                                         .Iadd.R.sup.1 OH.Iaddend.of                                                  .[.R.sub.1 OH.].of                                                            removalConditions                                                                         ##STR37##                                                                             Δ.sup.3                                                                -)(Δ.sup.                                                               4 -/Yield**        __________________________________________________________________________    16 R.sup.1 = C.sub.2 H.sub.5 (12)                                                         Chloro- form (200)                                                                 Cumene Hydro- peroxide (0.5)                                                       130° C., 14 hr                                                               ##STR38##                                                                             (65.2)                                                                            Conc. H.sub.2 SO.sub.4 0.1 g No                                               solvent 90° C., 8                                                                 87.0    (33/67)            17 R.sup.1 = C.sub.2 H.sub.5 (12)                                                         Bromo- form (50)                                                                   t-Butyl hydro- peroxide (0.2)                                                      120° C.,  14 hr                                                              ##STR39##                                                                             (74.5)                                                                            V.sub.2 O.sub.5 0.2 g C.sub.6                                                 H.sub.6 25 ml reflux, 3                                                                  86.2    (31/69)            18 R.sup.1 = cyclohexyl (15)                                                              Chloro- form (200)                                                                 BPO (0.4)                                                                          130° C., 20 hr                                                               ##STR40##                                                                             (70.2)                                                                            conc. H.sub.2 SO.sub.4 0.3 g                                                  C.sub.6 H.sub.6 25 ml reflux, 6                                               hr         80.4    (32/68)            __________________________________________________________________________     *Each yield value was determined by gaschromatographic analysis of the        concentration residue.                                                        **Each yield value represents the yield of distillative isolation. The        Δ.sup.4 -/Δ.sup.3 - values in parentheses denote the ratios o     1,1,1trihalogeno-4-methyl-4-pentene to                                        1,1,1trihalogeno-4-methyl-3-pentene.                                     

EXAMPLE 19

A glass tube, 1.5 cm in inside diameter and 30 cm long, was packed with2% vanadium pentoxide-on-Kieselguhr and, then, externally heated byribbon heater to establish an internal temperature of 130°-135° C. Tothis tube was fed a solution of 50 g of1,1,1-trichloro-4-methyl-4-pentanol in 50 ml of toluene at a rate of 30ml/hr. and the distillate was cooled by condenser and trapped. Thedistillate was dried over magnesium sulfate and the solvent wasdistilled off under reduced pressure. Gas-chromatographic analysis ofthe residue revealed that the conversion of1,1,1-trichloro-4-methyl-4-pentanol was 93.6%, the selectively for thecontemplated 1,1,1-trichloro-4-methyl-4-pentene and1,1,1-trichloro-4-methyl-3-pentene was 98.7% and the ratio of the4-pentene to the 3-pentene was 43:57.

EXAMPLE 20

A three-necked flask of 200 ml capacity was filled with 68 g of isopreneand, at 0°-3° C. 1.0 mole of dry hydrogen chlorine gas was introduced.Following the reaction, the system was further stirred at the sametemperature for an hour and, then, distilled under reduced pressure.From the fraction boiling at 46°-47° C. (214 mmHg) was obtained 79.0 g(yield 76%) of 1,2-prenyl chloride. A 20.8 g portion of this1,2-prenylchloride was dissolved in 79 g of bromotrichloromethane,followed by the addition of 1.2 g of benzoyl peroxide. The reaction wasthus carried out at 80°±2° C. for 16 hours. The reaction mixture wasdirectly distilled under reduced pressure to obtain 9.7 of1,1,1-trichloro-4-methyl-3-pentene (26% from 1,2-prenyl chloride) as afraction boiling at 77°-78° C. (20 mmHg) and 37.2 g of1,1,1,4-tetrachloro-3-bromo-4 -methylpentane (62% from 1,2-prenylchloride) as a fraction boiling at 89°-91° C. (1.2 mmHg).

By the procedure described in Example 1, the above1,1,1-trichloro-4-methyl-3-pentene was structurally identified with the1,1,1-trichloro-4-methyl-3-pentene obtained in Example 1. The structuralidentification for 1,1,1,4-tetrachloro-3-bromo-4-methylpentane wascarried out by the following procedures.

    ______________________________________                                         ##STR41##                                                                    Mass spectrum                                                                  ##STR42##                                                                    Nuclear magnetic .Iadd.resonance.Iaddend. .[.resonance .]. spectrum:          δ (in CCl.sub.4, ppm)                                                    ##STR43##                                                                    ______________________________________                                    

EXAMPLES 21 to 27

Various tertiary allyl halides were each subjected to radical reactionwith bromotrichloromethane or carbon tetrachloride under variousconditions. The results are set forth in Table 3. All reactions wereconducted in an inert gaseous atmosphere.

                                      TABLE 3                                     __________________________________________________________________________     Ex.                                                                              ##STR44##                                                                            (g)                                                                               ##STR45##                                                                           (g)                                                                              (g)initiatorRadical                                                                  reactionofConditions                                                                 ##STR46##                                                                               (%)                                                                              ##STR47##                                                                               (%)              __________________________________________________________________________    21                                                                                ##STR48##                                                                           (10.4)                                                                            BrCCl.sub.3                                                                         (50)                                                                             t-Butyl  perbenzoate (0.5)                                                           105° C., 13 hr                                                                 ##STR49##                                                                              (43)                                                                              ##STR50##                                                                              (32)              22 "      (") "     (")                                                                              di-t-Butyl                                                                           80° C., 16 hr                                                                 "         (14)                                                                             "         (67)                                     peroxide (0.6)                                         23 "      (") "     (")                                                                              BPO (0.5)                                                                            90° C., 24 hr                                                                 "         (18)                                                                             "         (64)              24 "      (") "     (")                                                                              Methyl ethyl                                                                         80° C., 32 hr                                                                 "         (11)                                                                             "         (45)                                     ketone                                                                        peroxide (0.4)                                         25 "      (") CHCl.sub.3                                                                          (300)                                                                            di-t-Butyl peroxide (0.5)                                                            100° C., 48 hr                                                                "         (24)                                                                              ##STR51##                                                                              (33)              26 "      (") CCl.sub.4                                                                           (200)                                                                            t-Butyl perbenzoate (0.5)                                                            100° C., 40 hr                                                                "         (25)                                                                              ##STR52##                                                                              (38)              27 "      (") CBr.sub.4                                                                           (40)                                                                             t-Butyl perbenzoate (0.4)                                                            90° C., 6 hr                                                                   ##STR53##                                                                              (10)                                                                              ##STR54##                                                                              (72)              __________________________________________________________________________     *Identified by the gas chromatographic retention time which was the same      as that of an authentic sample obtained by introduction of dry hydrogen       chloride into 1,1,1trichloro-4-methyl-3-pentene.                              **Identified by the gas chromatographic retention time which was the same     as that of an authentic sample obtained by introduction of chlorine gas       into 1,1,1trichloro-4-methyl-3-pentene.                                  

EXAMPLE 28

In 4,000 g of chloroform was dissolved 400 g of dimethyl vinyl carbinoland, following the addition of 30 g of tert-butyl perbenzoate, thesolution was reacted at 110° C. for 30 hours. After that time, theunreacted dimethyl vinyl carbinol and chloroform were removed bydistillation under reduced pressure. As the residue was obtained 835 gof a reddish-yellow viscous fluid.

Gas-chromatographic analysis of this product revealed that the purity of1,1,1-trichloro-4-methyl-4-pentanol was 90.4%, the amount of impurity1,1,3-trichloro-4-methyl-4-pentanol being 8.7%.

The above residue was distilled in vacuo to obtain 732 g of high-purity1,1,1-trichloro-4-methyl-4-pentanol as a fraction boiling at 60°-61.5°C. (0.3 mmHg). This product, on standing, provides white crystals.

The structural identification for 1,1,1-trichloro-4-methyl-4-pentanolwas carried out in the same manner as Example 1. The above product wasfound to be identical with the 1,1,1-trichloro-4-methyl-4-pentanolobtained in Example 1.

Then, to 732 g of 1,1,1-trichloro-4-methyl-4-pentanol was added 7.3 g ofp-toluenesulfonic acid and the mixture was heated at 155°-160° C. for1.5 hours, the byproduct water being azeotropically removed. Thereaction mixture was as such distilled under a reduced pressure of 200mmHg and the distillate was dried over sodium sulfate and fractionallydistilled. By the above procedure was obtained 62 g of1,1,1-trichloro-4-methyl-4-pentene as a fraction boiling at 73°-74° C.(20 mmHg), together with 536 g of 1,1,1-trichloro-4-methyl-3-pentene asa fraction boiling at 74°-77° C. (20 mmHg).

The structural identification for 1,1,1-trichloro-4-methyl-4-pentene and1,1,1-trichloro-4-methyl-3-pentene was carried out by the sameprocedures as those described in Example 1. These compounds were inagreement with the 1,1,1-trichloro-4-methyl-4-pentene and1,1,1-trichloro-4-methyl-3-pentene, respectively, of Example 1.

A three-necked flask of 500 ml capacity was filled with 186 g of theabove 1,1,1-trichloro-4-methyl-3-pentene and, on a water bath, 183 g of1,5-diazabicyclo[5,4,0]undecene-5(DBU) was added dropwise. After thedropwise addition was completed, the mixture was reacted at roomtemperature for 1 hour and, then, at 70° C. for 2 hours. The reactionmixture thus obtained was poured in 500 ml of water and extracted withether. The extract was rinsed with water, dehydrated and distilled underreduced pressure to remove the solvent. The residue was furtherdistilled in vacuo to recover 137 g of.[.1,1-dichloro-4,4-dimethylbutandiene.]..Iadd.1,1-dichloro-4,4-dimethylbutadiene .Iaddend.as a fraction boiling64°-65° C.(20 mmHg). The structure of this compound was identified bythe following methods.

    ______________________________________                                         ##STR55##                                                                    Infrared absorption spectrum:                                                  ##STR56##                                                                    Mass spectrum:                                                                 ##STR57##                                                                    Nuclear magnetic resonance spectrum: (in CCl.sub.4, ppm)                       ##STR58##                                                                    ______________________________________                                    

EXAMPLE 29

A three-necked flask of 300 ml capacity was filled with 130.2 g of1,1,1-trichloro-4-methyl-3-pentene as obtained by a procedure similar tothat described in Example 1 and a solution of 23 g of sodium metal in150 ml of methanol was added dropwise at 65° C. After the dropwiseaddition had been completed, the reaction was further continued at thattemperature for 3 hours. After cooling, the resultant crystals wereremoved by filtration under reduced pressure. The filtrate wasconcentrated to 150 ml under reduced pressure, poured in water andextracted with ether. The extract was rinsed with a saturated aqueoussolution of sodium chloride, dehydrated, and distilled under reducedpressure to remove the solvent. On vacuum distillation of the residue,there was obtained 98.7 g of 1,1-dichloro-4,4-dimethylbutadiene.

EXAMPLE 30

To 65 g of 1,1,1-trichloro-4-methyl-3-pentene was added 30 g of powderedpotassium hydroxide and, under stirring, the reaction was carried out at120°-125° C. for 5 hours. The reaction mixture was allowed to cool and,then, poured in water, followed by extraction with ether. The extractwas rinsed with water and dehydrated. The solvent was then distilled offunder reduced pressure and the residue was subjected to vacuumdistillation. By the described procedure was obtained 46.7 g of1,1-dichloro-4,4-dimethylbutadiene.

EXAMPLES 31-38 ##STR59##

As in Example 28, each compound [III] was heated in the presence of anacid catalyst to remove R'OH and the resultant compound [I] wasfractionated by distillation to isolate1,1,1-trihalogeno-4-methyl-3-pentene. This last-mentioned compound wasreacted with a basic reagent to obtain the corresponding1,1-dihalogeno-4,4-dimethylbutadiene. The results are set forth in Table4. The compounds [III] employed were each synthesized by reacting thecorresponding ##STR60## in 10 times its weight of chloroform and in thepresence of a radical initiator at a temperature in the range of 100° to130° C.

                                      TABLE 4                                     __________________________________________________________________________     ##STR61##                                                                     Ex.                                                                              (mole)[III]Compound                                                                   (mole %)*catalystAcid                                                                 of R'OHof removalConditions                                                          for compound [I]% Selectivitycompound [III]%                                 Conversion of                                                                           ##STR62##                                 __________________________________________________________________________    31                                                                                ##STR63##                                                                            Lauryl sulfonate (1.0)                                                                155° C., 2 hrs.                                                               98.8 99.0                                                                              15:85                                      32 "       H.sub.2 SO.sub.4                                                                      130° C., 4 hrs.                                                               98.4     20:80                                                 (0.5)          96.5                                                33 "       V.sub.2 O.sub.5                                                                       140° C., 3 hrs.                                                               93.1     25:75                                                 (1.5)          97.7                                                34                                                                                ##STR64##                                                                            p-Toluenesul- fonic acid (0.7)                                                        160° C., 1.5 hr.                                                              97.2 97.9                                                                              15:85                                      35                                                                                ##STR65##                                                                            p-Toluenesul- fonic acid (0.7)                                                        160° C., 1.5 hr.                                                              92.4 96.0                                                                              "                                          36                                                                                ##STR66##                                                                            H.sub.2 SO.sub.4                                                                      130° C., 3 hrs.                                                               96.7 95.4                                                                              22:78                                      37 "       V.sub.2 O.sub.5                                                                       140° C., 3 hrs.                                                               97.3     27:73                                                 (1.5)          95.7                                                38                                                                                ##STR67##                                                                            p-Toluenesul- fonic acid (0.7)                                                        150° C., 2 hrs.                                                               96.8 93.4                                                                              17:83                                      __________________________________________________________________________                     ##STR68##                                                                       Compound [I]                                                                          Base Conditions of removal                                                                    Compound [II],                                     Ex.                                                                              (mole)  (mole)                                                                             of hydrogen halide                                                                       % yield**                          __________________________________________________________________________                    31                                                                                ##STR69##                                                                            DBN  Room temp., 1.5 hrs. 65° C., 2.5                                       hrs.       93.2                                               32 "       NaNH.sub.2                                                                         70° C., 4 hrs.                                                                    88.9                                               33 "       Ca(OH).sub.2                                                                       110° C., 4 hrs.                                                                   90.2                                               34 "       DBU  Room temp., 1.5 hrs.                                                                     94.6                                                               65° C., 2.0 hrs.                                       35 "       NaOMe                                                                              65° C., 5 hrs.                                                                    91.2                                               36                                                                                ##STR70##                                                                            NaOEt                                                                              70° C., 5 hrs.                                                                    92.0                                               37 "       NaOBu.sup.t                                                                        "          87.1                                               38 "       KOBu.sup.t                                                                         60° C., 3 hrs.                                                                    93.4                               __________________________________________________________________________     [Notes]-                                                                      *Mole % of catalyst based on compound                                         **Yield from compound [I]-                                               

We claim as our invention: .[.1. A 1,1,1-trihalogeno-4-methylpentene ofthe formula.]. ##STR71## .[.wherein X¹, X² and X³ are the same ordifferent and each represents a halogen atom and Z is a group of theformula.]. ##STR72## .[.or a group of the formula.]. ##STR73## .[.2. A1,1,1-trihalogeno-4-methylpentene as set forth in claim 1, which has theformula:.]. ##STR74## .[.3. A 1,1,1-trihalogeno-4-methylpentene as setforth in claim 1, which has the formula:.]. ##STR75##
 4. A process forproducing a 1,1,1-trihalogeno-4-methylpentene of the formula ##STR76##wherein Z is a group of the formula ##STR77## or a group of the formula##STR78## and X¹, X² and X³ are the same or different and eachrepresents a halogen atom, which comprises removing R¹ OH from acompound of the formula ##STR79## wherein R¹ is a hydrogen atom or analkyl, cycloalkyl, aryl, aralkyl or acyl group; and X¹, X² and X³ are asdefined above in the presence .[.of an effective amount of an acidcatalyst or.]. of an effective amount of at least one member selectedfrom the group consisting silica gel, aluminum silicate, kieselguhr,pumice, Fuller's earth, activated alumina and activated carbon. .[.5. Aprocess as set forth in claim 4 wherein the reaction is carried out at atemperature of from room temperature to about 160° C. in the presence of0.01 to 30%, based on the weight of said compound of formula III, of anacid catalyst..]. .[.6. A process as set forth in claim 5 wherein thetemperature is from room temperature to 120° C..]. .[.7. A process asset forth in claim 5 wherein said acid catalyst is present in an amountwithin the range of 0.1 to 10%..].
 8. A process as set forth in claim.[.5.]. .Iadd.4 .Iaddend.wherein the reaction is carried out at atemperature of from 80° to 250° C. in gaseous or liquid phase .[.in thepresence of at least one member selected from the group consisting ofsilica gel, aluminum silicate, kieselguhr, pumice, Fuller's earth,activated alumina and activated carbon..].
 9. A process for producing a1,1,1-trihalogeno-4-methyl-3-pentene, which comprises removing R¹ OHfrom a compound of the formula ##STR80## wherein R¹ is a hydrogen atomor an alkyl, cycloalkyl, aryl, aralkyl or acyl group and X¹, X² and X³are the same or different and each represents a halogen atom in thepresence of an effective amount of an acid catalyst or of an effectiveamount of at least one member selected from the group consisting ofsilica gel, aluminum silicate, kieselguhr, pumice, Fuller's earth,activated alumina and activated carbon to obtain a mixture of a1,1,1-trihalogeno-4-methyl-4-pentene of the formula ##STR81## whereinX¹, X² and X³ are as defined above and a1,1,1-trihalogeno-4-methyl-3-pentene of the formula ##STR82## whereinX¹, X² and X³ are as defined above and subjecting said mixture tofractional distillation to isolate said1,1,1-trihalogeno-4-methyl-3-pentene with a first-emerging fraction richin said 1,1,1-trihalogeno-4-methyl-4-pentene being recycled to thereaction system.
 10. A process as set forth in claim 9 wherein thereaction is carried out at a temperature of from room temperature toabout 160° C. in the presence of 0.01 to 30%, based on the weight ofsaid compound of formula III, of an acid catalyst.
 11. A process as setforth in claim 10 wherein the temperature is from room temperature to120° C.
 12. A process as set forth in claim 10 wherein said acidcatalyst is present in an amount within the range of 0.1 to 10%.
 13. Aprocess as set forth in claim 9 wherein the reaction is carried out at atemperature of from 80° to 250° C. in gaseous or liquid phase in thepresence of at least one member selected from the group consisting ofsilica gel, aluminum silicate, kieselguhr, pumice, Fuller's earth,activated alumina and activated carbon.
 14. A process for producing a1,1,1-trihalogeno-4-methylpentene of the formula ##STR83## wherein X¹,X² and X³ are the same or different and each represents a halogen atomand Z is a group of the formula ##STR84## or a group of the formula##STR85## which comprises adding a haloform to a dimethyl vinyl carbinolcompound of the formula ##STR86## wherein R¹ is a hydrogen atom or analkyl, cycloalkyl, aryl, aralkyl or acyl group under radical-reactionconditions to obtain a compound of the formula ##STR87## wherein R¹, X¹,X² and X³ are as defined above and removing R¹ OH from thelast-mentioned compound III in the presence .[.of an effective amount ofan acid catalyst or.]. of an effective amount of at least one memberselected from the group consisting of silica gel, aluminum silicate,kieselguhr, pumice, Fuller's earth, activated alumina and activatedcarbon. .[.15. A process as set forth in claim 14 wherein the reactionis carried out at a temperature of from room temperature to about 160°C. in the presence of 0.01 to 30%, based on the weight of said compoundof formula III, of an acid catalyst..]. .[.16. A process as set forth inclaim 15 wherein the temperature is from room temperature to 120° C..]..[.17. A process as set forth in claim 15 wherein said acid catalyst ispresent in an amount within the range of 0.1 to 10%..].
 18. A process asset forth in claim 14 wherein the reaction is carried out at atemperature of from 80° to 250° C. in gaseous or liquid phase .[.in thepresence of at least one member selected from the group consisting ofsilica gel, aluminum silicate, kieselguhr, pumice, Fuller's earth,activated alumina and activated carbon..].
 19. A process as set forth inclaim 14 wherein R¹ in formula IV is a hydrogen atom.
 20. A process asset forth in claim 14 wherein said haloform is chloroform or bromoform.21. A process as set forth in claim 14 wherein the reaction under saidradical-reaction conditions is conducted in the presence of aradical-reaction initiator and at a temperature in the range of 70° to180° C.
 22. A process as set forth in claim 14 wherein the reactionunder said radical-reaction conditions is conducted under irradiationand at a temperature in the range of room temperature to 100° C.
 23. Aprocess for producing a 1,1,1-trihalogeno-4-methyl-3-pentene of theformula ##STR88## wherein X¹, X² and X³ are the same or different andeach represents a halogen atom, which comprises isomerizing a1,1,1-trihalogeno-4-methyl-4-pentene of the formula ##STR89## whereinX¹, X² and X³ are as defined above by heating at a temperature of from80° to 200° C. in the presence of 0.001 to 30%, based on the weight ofsaid 1,1,1-trihalogeno-4-methyl-4-pentene, of at least one memberselected from the group consisting of a transition metal of Group 6B,Group 7B or Group 8 of the Periodic Table of the Elements, a compound ofsaid transition metal and an acid catalyst.
 24. A process as set forthin claim 23 wherein said temperature is in the range of 110° to 170° C.25. A .[.processas.]. .Iadd.process as .Iaddend.set forth in claim 23wherein the proportion of any of said transition metals and compounds oftransition metals or of said acid catalyst is in the range of 0.1 to 10weight percent.
 26. A process for producing a1,1-dihalogeno-4-methyl-1,3-pentadiene of the formula ##STR90## whereinX and Y are the same or different and each represents a halogen atom,which comprises treating a 1,1,1-trihalogeno-4-methyl-3-pentene of theformula ##STR91## wherein X¹, X² and X³ are the same or different andeach represents a halogen atom with a basic reagent at a temperature offrom room temperature to 150° C.
 27. A process as set forth in claim 26wherein said basic reagent is at least one member selected from thegroup consisting of an alkali or alkaline earth metal hydroxide, a metalalcoholate, an alkali metal hydride, an alkali metal amide, an amine andan organolithium compound.
 28. A process as set forth in claim 27wherein said basic reagent is an alkali metal alcoholate, alkali metalhydride or alkali metal hydroxide.
 29. A process as set forth in claim26 wherein said temperature is from 50° to 130° C.
 30. A process forproducing a 1,1-dihalogeno-4-methyl-1,3-pentadiene of the formula##STR92## wherein X and Y are the same or different and each representsa halogen atom, which comprises adding a haloform to a dimethyl vinylcarbinol compound of the formula ##STR93## wherein R¹ is a hydrogen atomor an alkyl, cycloalkyl, aryl, aralkyl or acyl group underradical-reaction conditions to obtain a compound of the formula##STR94## wherein R¹ is as defined above and X¹, X² and X³ are the sameor different and each represents a halogen atom; removing R¹ OH from thecompound III in the presence of an effective amount of an acid catalystor an effective amount of at least one member selected from the groupconsisting of silica gel, aluminum silicate, kieselguhr, pumice,Fuller's earth, activated alumina and activated carbon to obtain amixture of a 1,1,1-trihalogeno-4-methyl-4-pentene of the formula##STR95## wherein X¹, X² and X³ are as defined above and a1,1,1-trihalogeno-4-methyl-3-pentene of the formula ##STR96## whereinX¹, X² and X³ are as defined above; subjecting said mixture tofractional distillation to isolate said1,1,1-trihalogeno-4-methyl-3-pentene and treating said1,1,1-trihalogeno-4-methyl-3-pentene with a basic reagent at atemperature of from room temperature to 150° C.
 31. A process as setforth in claim 30 wherein R¹ in formula IV is a hydrogen atom.
 32. Aprocess as set forth in claim 30 wherein said haloform is chloroform orbromoform.
 3. A process as set forth in claim 30 wherein the reactionunder said radical-reaction conditions is conducted in the presence of aradical-reaction initiator and at a temperature in the range of 70° to180° C.
 34. A process as set forth in claim 30 wherein the reactionunder said radical-reaction conditions is conducted under irradiationand at a temperature in the range of room temperature to 100° C.
 35. Aprocess as set forth in claim 30 wherein the removal of R¹ OH is carriedout at a temperature of from room temperature to about 160° C. in thepresence of 0.01 to 30%, based on the weight of said compound of formulaIII, of an acid catalyst.
 36. A process as set forth in claim 35 whereinthe temperature is from room temperature to 120° C.
 37. A process as setforth in claim 35 wherein said acid catalyst is present in an amountwithin the range of 0.1 to 10%.
 38. A process as set forth in claim 30wherein the removing of R¹ OH is carried out at a temperature of from80° C. to 250° C. in gaseous or liquid phase in the presence of at leastone member selected from the group consisting of silica gel, aluminumsilicate, kieselguhr, pumice, Fuller's earth, activated alumina andactivated carbon.
 39. A process as set forth in claim 30 wherein thebasic reagent is at least one member selected from the group consistingof an alkali or alkaline earth metal hydroxide, a metal alcoholate, analkali metal hydride, an alkali metal amide, an amine and anorganolithium compound.
 40. A process as set forth in claim 39 whereinsaid basic reagent is an alkali metal alcoholate, alkali metal hydrideor alkali metal hydroxide.
 41. A process as set forth in claim 30wherein the treatment with a basic reagent is carried out at atemperature of from 50° to 130° C. .Iadd.
 42. A process for producing a1,1,1-trihalogeno-4-methylpenetene of the formula ##STR97## wherein Z isa group of the formula ##STR98## or a group of the formula ##STR99## andX¹, X² and X³ are the same or different and each represents a halogenatom, which comprises removing R¹ OH from a compound of the formula##STR100## wherein R¹ is a hydrogen atom or an alkyl, cycloalkyl, aryl,aralkyl or acyl group; and X¹ X² and X³ are as defined above, in thepresence of an effective amount of at least one acid catalyst selectedfrom the group consisting of sulfuric acid, phosphoric acid,p-toluenesulfonic acid, lauryl sulfonate, phosphorus pentoxide, vanadiumpentoxide and wolfram trioxide. .Iaddend..Iadd.
 43. A process as setforth in claim 42 wherein the reaction is carried out at a temperatureof from room temperature to about 160° C. in the presence of 0.01 to30%, based on the weight of said compound of formula III, of saidcatalyst. .Iaddend..Iadd.
 44. A process as set forth in claim 43 whereinthe temperature is from room temperature to 120°C. .Iaddend. .Iadd. 45.A process as set forth in claim 43 wherein said catalyst is present inan amount within the range of 0.1 to 10%. .Iaddend..Iadd.
 46. A processfor producing a 1,1,1-trihalogeno-4-methyl-pentene of the formula##STR101## wherein X¹, X², and X³ are the same or different and eachrepresents a halogen atom and Z is a group of the formula ##STR102## ora group of the formula ##STR103## which comprises adding a haloform to adimethyl vinyl carbinol compound of the formula ##STR104## wherein R¹ isa hydrogen atom or an alkyl, cycloalkyl, aryl, aralkyl or acyl group,under radical-reaction conditions to obtain a compound of the formula##STR105## wherein R¹, X¹ X² and X³ are as defined above, and removingR¹ OH from the last-mentioned compound III in the presence of aneffective amount of at least one acid catalyst selected from the groupconsisting of sulfuric acid, phosphoric acid, p-toluene-sulfonic acid,lauryl sulfonate, phosphorus pentoxide, vanadium pentoxide and wolframtrioxide. .Iaddend..Iadd.
 47. A process as set forth in claim 46 whereinthe reaction is carried out at a temperature of from room temperature toabout 160° C. in the presence of 0.01 to 30%, based on the weight ofsaid compound of formula III, of said catalyst. .Iaddend..Iadd.
 48. Aprocess as set forth in claim 47 wherein the temperature is from roomtemperature to 120° C. .Iaddend..Iadd.
 49. A process as set forth inclaim 47 wherein said catalyst is present in an amount within the rangeof 0.1 to 10%. .Iaddend.